摘要:
A process for decoking of a process that cracks hydrocarbon feedstock containing resid and coke precursors, wherein steam is added to the feedstock to form a mixture which is thereafter separated into a vapor phase and a liquid phase by flashing in a flash/separation vessel, separating and cracking the vapor phase, and recovering cracked product. Coking of internal surfaces in and proximally downstream of the vessel is controlled by interrupting the feed flow, purging the vessel with steam, introducing an air/steam mixture to at least partially combust the coke, and resuming the feed flow when sufficient coke has been removed. An apparatus for carrying out the process is also provided.
摘要:
A process for decoking of a process that cracks hydrocarbon feedstock containing resid and coke precursors, wherein steam is added to the feedstock to form a mixture which is thereafter separated into a vapor phase and a liquid phase by flashing in a flash/separation vessel, separating and cracking the vapor phase, and recovering cracked product. Coking of internal surfaces in and proximally downstream of the vessel is controlled by interrupting the feed flow, purging the vessel with steam, introducing an air/steam mixture to at least partially combust the coke, and resuming the feed flow when sufficient coke has been removed. An apparatus for carrying out the process is also provided.
摘要:
A highly efficient vapor/liquid separation apparatus for treating a flow of vapor/liquid mixtures of hydrocarbons and steam comprises a substantially cylindrical vertical drum having an upper cap section, a middle section comprising a circular wall, a lower cap section, a tangential inlet to introduce hydrocarbon/steam mixtures, an overhead vapor outlet, and a bottom outlet for liquid. The vessel also comprises an annular structure located in the middle section, comprising i) an annular ceiling section extending from the circular wall and ii) a concentric internal vertical side wall to which the ceiling section extends. The annular structure blocks upward passage of vapor/liquid mixtures along the circular wall beyond the ceiling section, and surrounds an open core having sufficient cross-sectional area to permit vapor velocity low enough to avoid significant entrainment of liquid.
摘要:
The present disclosure provides a process for treating a hydrocarbon feedstock comprising: (a) feeding the hydrocarbon feedstock at a linear velocity equal to or less than 0.9 m/s to a first preheating zone in the convection section of a steam cracking furnace; (b) preheating the hydrocarbon feedstock in the first preheating zone to vaporize less than 99 wt. % of the hydrocarbon feedstock to form a vapor-liquid mixture; (c) separating at least a portion of the vapor-liquid mixture to form a vapor fraction and a liquid fraction; and (d) feeding at least a portion of the vapor fraction to the steam cracking furnace.
摘要:
A highly efficient vapor/liquid separation apparatus for treating a flow of vapor/liquid mixtures of hydrocarbons and steam comprises a substantially cylindrical vertical drum having an upper cap section, a middle section comprising a circular wall, a lower cap section, a tangential inlet to introduce hydrocarbon/steam mixtures, an overhead vapor outlet, and a bottom outlet for liquid. The vessel also comprises an annular structure located in the middle section, comprising i) an annular ceiling section extending from the circular wall and ii) a concentric internal vertical side wall to which the ceiling section extends. The annular structure blocks upward passage of vapor/liquid mixtures along the circular wall beyond the ceiling section, and surrounds an open core having sufficient cross-sectional area to permit vapor velocity low enough to avoid significant entrainment of liquid.
摘要:
A process for cracking a hydrocarbon feedstock containing salt and/or particulate matter, wherein said hydrocarbon feedstock containing salt and/or particulate matter is heated, then separated into a vapor phase and a liquid phase by flashing in a flash/separation vessel, separating and cracking the vapor phase which comprises less than about 98% of the hydrocarbon feedstock containing salt and/or particulate matter, and recovering cracked product. The salt and/or particulate matter are removed in the liquid bottoms stream from the flash/separation vessel.
摘要:
A process and control system for cracking a heavy hydrocarbon feedstock containing non-volatile hydrocarbons comprising heating the heavy hydrocarbon feedstock, mixing the heated heavy hydrocarbon feedstock with a dilution steam stream to form a mixture stream having a vapor phase and a liquid phase, separating the vapor phase from the liquid phase in a separation vessel, and cracking the vapor phase in the furnace, wherein the furnace draft is continuously measured and periodically adjusted to control the temperature of the stream entering the vapor/liquid separator and thus controlling the ratio of vapor to liquid separated in the separation vessel; and wherein in a preferred embodiment the means for adjusting the draft comprises varying the speed of at least one furnace fan, possibly in combination with adjusting the position of the furnace fan damper(s) or the furnace burner dampers(s).
摘要:
A vapor/liquid separation apparatus for treating a flow of vapor/liquid mixtures of hydrocarbons and steam comprises a vertical drum with a side inlet to introduce hydrocarbon/steam mixtures, an overhead vapor outlet, and a lower section in communication with a cylindrical boot of less diameter than the drum, the boot comprising sufficient gas-liquid contact surface, e.g., that provided by one or more sheds, baffles and/or distillation trays, to provide at least a partial theoretical distillation stage, and a lower portion for receiving liquid from the drum, a lower outlet for removing the liquid, and an inlet for introducing a stripping gas such as steam, hydrogen, light crackable hydrocarbon, and/or methane, below the distillation tray and preferably above the level of liquid in the boot.
摘要:
A vapor/liquid separation apparatus for treating a flow of vapor/liquid mixtures of hydrocarbons and steam comprises a vertical drum with a side inlet to introduce hydrocarbon/steam mixtures, an overhead vapor outlet, and a lower section in communication with a cylindrical boot of less diameter than the drum, the boot comprising sufficient gas-liquid contact surface, e.g., that provided by one or more sheds, baffles and/or distillation trays, to provide at least a partial theoretical distillation stage, and a lower portion for receiving liquid from the drum, a lower outlet for removing the liquid, and an inlet for introducing a stripping gas, such as steam, hydrogen, light crackable hydrocarbon, and/or methane, below the distillation tray and preferably above the level of liquid in the boot.
摘要:
A process for cracking a heavy hydrocarbon feedstock containing non-volatile components and/or coke precursors, wherein a stripping agent is added to the feedstock to form an enhanced hydrocarbon blend which is thereafter separated into a vapor phase and a liquid phase by flashing in a flash/separation vessel, separating and cracking the vapor phase, and recovering cracked product. The stripping agent increases vaporization of the volatile fraction of the heavy hydrocarbon increasing the maximum feedrate capacity of the furnace.